1. Field of the Invention
The present invention relates generally to a method for recovering an object to be treated.
2. Related Background Art
In conventional semiconductor production processes, there has been used a multi-chamber treatment system serving as a so-called cluster tool, which comprises a common transfer chamber, and various treatment chambers and cassette chambers which are arranged around the common transfer chamber to be connected thereto.
In such a treatment system, an object to be treated, which is received in a cassette housed in a cassette chamber is first transported to a common transfer chamber by means of a transport unit, such as a transport arm, which is provided in the common transfer chamber. Then, after the object is positioned by means of a positioning unit provided in the common transfer chamber, the object is transported to a predetermined treatment chamber by means of the transport arm. Then, a predetermined treatment, such as an etching treatment, is carried out for the object transported into the treatment chamber. Moreover, the object is transported to another treatment chamber via the common transfer chamber by means of the transport arm, and a predetermined treatment, such as, a thin film deposition treatment, is carried out for the object. Thereafter, the treated object is transported from the treatment chamber into a post-treatment chamber, such as a cooling chamber, via the common transfer chamber by means of the transport arm, and a cooling treatment (a post-treatment) is carried out for the object. Then, the post-treated object is returned from the post-treatment chamber to the cassette chamber via the common transfer chamber.
As described above, after the treatment, such as the etching treatment, the object is transported into another treatment chamber via the common transfer chamber by means of the transport arm since the treatment, such as the etching treatment, does not require any post-treatments in the post-treatment chamber, and then, the predetermined treatment, such as the thin film deposition treatment, is carried out for the object. On the other hand, after the treatment, such as the thin film deposition treatment, the object is transported into the post-treatment chamber, such as the cooling chamber, via the common transfer chamber by means of the transport arm since the treatment, such as the thin film deposition treatment, requires the post-treatment in the post-treatment chamber, and then, the cooling treatment (the post-treatment) is carried out for the object.
By the way, when the treatment is stopped by some cause, e.g., a power failure or a forced interruption of the power supply, during the treatment of an object, there is the problem of how to recover the object in the treatment system into the cassette, except for objects housed in the cassette in the cassette chamber. That is, when the aforementioned some cause is solved, if the object is directly recovered into the cassette without carrying out an ordinary cooling treatment (a post-treatment) immediately after the thin film deposition treatment is carried out for the object by means of, e.g., a chemical vapor deposition (CVD) system, the cassette may be deformed or melted by the heat generated in the object by the thin film deposition treatment.
Therefore, when the treatment system is restarted after the treatment is stopped as described above, the object being treated or transported must be recovered into the cassette one by one, e.g., by the operator's manual operation.
However, in a case where the object existing in the system (except for objects housed in the cassette) is recovered by the operator's manual operation as described above, it is often very difficult for the operator to recognize all of the treatment history of the respective objects, e.g., to recognize which treatment was carried out for the object on the transport arm or if no treatment was carried out therefor. Therefore, in a case where the treatment system includes, e.g., a CVD system, when the operator can not recognize the treatment history of the object, it is required to recover the object in view of the influence of heat generated by the thin film deposition treatment, i.e., in view of the time required to cool the object, so that the recovery of the object is delayed.
In addition, even if the operator can recognize the treatment history of the respective objects, it is very difficult to recognize how to recover the respective objects existing, e.g., in the treatment chamber and the post-treatment chamber, and on the positioning system and the transport arm, and to recognize the order in which the respective objects are accurately and rapidly recovered. Such recognition often relies upon the skilled operator's experience and intuition.